Coordination compounds antitumor agents

Almost 40 years ago, cisplatin, a square planar coordination compound of platinum(II), was found to be an effective antitumor agent. It forms complexes with some of the nitrogen bases of DNA, producing mutations during the replication of cancer cells. Second-generation square-planar platinum(II) complexes such as carboplatin and oxaliplatin that have less severe side effects are now available. Octahedral platinum(IV) complexes such as satraplatin as well as triplatin, a tri-nuclear platinum(II) complex, are in various stages of development. A new class of ruthenium(III) anticancer complexes hold promise of targeting additional cancer types with fewer side effects. 

An efficient procedure for the synthesis of 2-methoxyestradiol was found by the same authors, based on Cp lr moiety.5,6,7,8-Tetrahydro-2-naphthol and /3-estradiol gave 7 -arene complexes with [Cp"lt(Solv)3](BF4)2 as described above. In the case of the complexed hormone, the Cp Ir moiety coordinates the A-ring either a (metal down) or /3 (metal up) relative to the Me group at C(13). The novel iridium cyclohexadienone compound of the complexed steroid was then oxidized by iodine to produce 2-methoxyestradiol, an anticancer agent which possesses important antitumor effects in vivo, in 60% overall yield from /3-estradiol. ... 

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